Bladed rotors such as those used, for example, as compressor rotors in the compressor area of a gas turbine rotor are often formed of multiple parts comprising individual disks which are connected to one another. Every stage of the compressor can be provided with its own disk or a plurality of rows of blades, each forming a stage, can be arranged on a disk which is known as a multidisk.
Multipart bladed rotors are known, for example, from EP 1 728 973 A1 or DE-OS 26 43 886, in which the individual disks are clamped together axially by tie rods and secured to one another so as to be centered relative to one another and fixed with respect to rotation relative to one another by Hirth serrations which are formed axially between the blade rows.
For mechanical reasons and in order to prevent interruptions in flow, a spur toothing of the kind mentioned above is usually arranged on a diameter which is smaller than the outer diameter of the rotor. In order to produce a radially inner spur toothing of this kind, a free space must be provided to allow sufficient room for the tool to be withdrawn. This disadvantageously increases cost on material, manufacturing and assembly because this free space must be closed with a corresponding filling piece when the rotor is assembled in order to prevent interference of the flow.
FIG. 2 is a partial cross-sectional view through the separating plane 7a of a multipart rotor according to the prior art in which a spur toothing 3a is arranged on a diameter that is smaller than the outer diameter of the rotor. A free space 10a is provided to accommodate the tool movement for producing the spur teeth and must be closed by a filling piece 11.
It is the object of the invention to provide an improved rotor for a flow machine.